Rheology of granular material under large pressures

In the hard-particle limit, granular rheology has been extensively studied in both experiments and simulation. Many applications, however, exist far from this limit and grains can experience significant stresses leading to elastic deformation, plasticity, and even fracture. To study granular rheology at large pressures, we use a bonded particle model where each grain is constructed out of a collection of smaller particles connected by a network of spring-like bonds. We first describe the initial compaction of grains to large pressures, highlighting where results differ from traditional discrete element method simulations, before shearing systems across a wide range of rates and pressures. With increasing pressure, deviations from traditional rheological models, such as the μ(I) rheology, emerge. The elastic deformation of individual grains and their evolving contact network are also quantified and discussed.

 

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525.